MECHANISM OF SUPPRESSION OF REPRODUCTIVE FUNCTION BY STRESS: ELECTROPHYSIOLOGICAL STUDY

在压力条件下，已知生殖功能会受到抑制。在本研究中，通过多单位活动（MUA）记录技术，在大鼠中研究了巨噬细胞和星形胶质细胞响应侵入性刺激而分泌的肿瘤坏死因子（TNF）对下丘脑促性腺激素释放激素（GnRH）脉冲发生器电活动的影响。与黄体生成素 (LH) 的脉动分泌相关的 MUA 特征性增加（突然）。是在治疗前对照期间记录的。在静脉内或心室内注射TNF后，MUA以固定间隔发生约一小时，但此后间隔延长几个小时，然后恢复到对照水平。 MUA 齐射的这些变化通过脉动的 LH 分泌如实反映。另一方面，吲哚美辛预处理阻断了 TNF 对 MUA 攻击间隔的影响。这些结果表明，外周组织或大脑中产生的 TNF 会导致 GnRH 脉冲频率降低，从而抑制生殖功能，并且 TNF 对下丘脑 GnRH 脉冲发生器的作用可能是由前列腺素介导的。

Under stress conditions, reproductive function is known to be suppressed. In the present study, the effect of tumor necrosis factor (TNF), which is secreted from macrophages and astrocytes in response to invasive stimuli, on the electrical activity of the hypothalamic gonadotropin-releasing hormone (GnRH) pulse generator was studied in the rat by means of multiunit activity (MUA) recording techniques. Characteristic increases (volleys) in MUA associated with pulsatile secretion of luteinizing hormone (LH). were recorded during a pretreatment control period. After either intravenous or intraventricular injection of TNF, MUA volleys occurred at regular intervals for about one hour, but thereafter the interval was prolonged for a few hours and then returned to control levels. These changes in MUA volleys were faithfully reflected by the pulsatile LH secretion. On the other hand, pretreatment with indomethacin blocked the effect of TNF on the interval between the MUA volleys. These results suggest that TNF, produced either in the peripheral tissue or in the brain, leads to a decrease in GnRH pulse frequency with a resultant suppression of reproductive function, and that the TNF action on hypothalamic GnRH pulse generator may be mediated by prostaglandins.